body {
    font-family: 'Microsoft YaHei', sans-serif;
    background-color: #f5f5f5;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 30px;
    width: 400px;
}

h2 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    color: #555;
}

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    box-sizing: border-box;
}

.captcha-container {
    display: flex;
    align-items: center;
}

.captcha-input {
    flex: 1;
    margin-right: 10px;
}

.captcha-img {
    width: 100px;
    height: 40px;
    background-color: #f0f0f0;
    border: 1px solid #ddd;
    border-radius: 4px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'Arial', sans-serif;
    font-size: 20px;
    letter-spacing: 2px;
    color: #333;
    cursor: pointer;
    user-select: none;
}

.btn {
    width: 100%;
    padding: 12px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #45a049;
}

.login-link {
    text-align: center;
    margin-top: 20px;
    color: #666;
}

.login-link a {
    color: #4CAF50;
    text-decoration: none;
}

.login-link a:hover {
    text-decoration: underline;
}

.error-message {
    color: #f44336;
    font-size: 14px;
    margin-top: 5px;
    display: none;
}
